[12] Established in July 1922, the MCPD is headquartered in Gaithersburg, Maryland, and in addition to its primary duties, it also provides aid and assistance to other police departments including the Metropolitan Police Department of the District of Columbia, and in neighboring jurisdictions such as the District of Columbia, Howard County, Baltimore City, and Prince George's County as requested by authority.

[6][7][13] The MCPD was established in early July 1922, absorbing some responsibilities from the Montgomery County Sheriff's Office (MCSO) through Chapter 259 of the Acts of 1922.

The first chief of the MCPD was Charles T. "Chas" Cooley, who was from Frederick County, Maryland and served as a soldier in the Spanish–American War.

From 1922 until 1935, the Montgomery County Board of Commissioners designated one police officer from within the MCPD's ranks to serve as its chief.

In 1935, through Chapter 9 of the Acts of 1935, the regulations were changed so that the chief could be appointed from any source, at the discretion of the Montgomery County Board of Commissioners.

He fought as a soldier in World War I and previous served in the Montgomery County Sheriff's Office as a deputy from 1925 to 1939.

[20] Also that same year, Robert DiGrazia, a former Boston Police Commissioner, became the MCPD's chief, intending to brings new changes to the department.

[22] However, in December 1994, Edwards was relieved of his position by Montgomery County Executive Douglas Duncan, who had taken office that same month, a move which angered the local chapter of the NAACP.

[21][22] On February 17, 1997, the local Fraternal Order of Police (FOP) body voted overwhelmingly in passing a resolution of no confidence in Mehrling's abilities as chief, claiming that she was not doing enough to defend MCPD officers against accusations of misconduct and abuse by the NAACP.

As a result of these allegations, the United States Department of Justice (DOJ) launched an investigation into the operations of the MCPD.

[30][31] Throughout much of the 1990s, the MCPD faced numerous allegations of abuse, excessive force, and misconduct, including fatal officer-involved shootings in Wheaton and Silver Spring in April 1999 and March 1999, respectively.

[32][6][33][34][35][36][30][31][37][38][39] Although there had been certain public scrutiny about specific police shootings involving MCP officers, it has been determined that they were all justified under the Constitution, federal and state laws, and department policy.

[41] On January 14, 2000, a Memorandum of Agreement (MOA) was signed between the U.S. Department of Justice and the MCP regarding abuses and misconduct committed by the latter.

King, on Moose's recommendation, was unanimously approved as the MCPD's assistant chief by the county council, after Alan G. Rodbell retired on December 23, 2001, to fill a law enforcement job position in Arizonan city of Scottsdale.

The county government objected in stating that the MCPD chief was not allowed to profit privately from official duties; the book itself was released on September 15, 2003.

During the sniper case, he was frequently criticized for his lack of public speaking abilities during interviews with the news media.

[46][47][48] On January 30, 2004, J. Thomas Manger, a former officer of the Fairfax County Police Department (FCPD), became the sixteenth MCPD chief.

The accused officers were alleged to have improperly billed Grady Management, a Silver Spring real estate firm, for more than 8,900 hours for which they also were compensated by the police.

The remodeling and moving phases took an extended period of time due to the legal requirements of housing a police district station along with administrative offices in the same building.

The building which houses the headquarters, located near Lake Placid, was built in the 1960s and was originally used by the National Geographic Society, and later by General Electric (GE).

Maryland legislature later passed Noah's Law which provides enhanced penalties for persons arrested for driving under the influence.

[65] In January 2021, members of the MCPD's SERT unit were present at the U.S. Capitol during the riot there by supporters of outgoing U.S. President Donald Trump.

The vehicles use LED lightbars with blue "steady-burn" diodes as an option during routine patrols for high visibility purposes, although it is currently not required by department policy.

The badge wording, from top to bottom, reads POLICE (RANK) MONTGOMERY COUNTY MD.

MCP also uses the Maryland coat of arms as the center piece of the badge instead of a full color state seal.

The national non-emergency contact number for the MCP and Montgomery County Emergency Communications Center (ECC) is (301) 279–8000.

When comparing Montgomery County to police staffing and population, it is slightly below the expected national average.

Development, traffic congestion and crime is at its peak, and there are currently plans at the state and local levels to address it.